Can I use multi-session to multi sftp servers simultaneously

Can I use multi-session to multi sftp servers simultaneously

Now I am trying to make my program to manipulate several sftp servers simultaneously. For the first step, I tried ListDirectory from 3 servers by using backgroundworker objects.
But it seemed not to work correctly.

So, I want to hear, if I can use .net assembly thread-safe or not , in order to know it was caused by my fault or not.